1. Field of the Invention
This invention relates to an improvement in gripper shuttles of the type used in weaving machines wherein the weft package remains outside the shed. The invention is more particularly concerned with a modification of the nose portion of such shuttles.
2. Description of the Prior Art
The known gripper shuttles normally comprise a tubular housing within which is mounted a gripper clamp. The lead end of such shuttles have a closed nose portion and an open trailing end. Normally, the nose, at least, is made of metal, such as steel and may be an integral part of the housing or may be a separate part secured to the front of the housing by welding or in some other known manner. As a rule, the nose has top and bottom surfaces which slope downwardly and upwardly respectively toward the longitudinal axis of the shuttle, the front edge has a transverse arcuate configuration and is blunt and rounded to facilitate passage of the shuttle through the teeth of a shuttle race which serves as a guide for the shuttle in its flight. The gripper clamp is generally U-shaped and has two spaced resiliently biased arms extending toward the trailing end of the housing and culminating in jaws adjacent the opening therein. During operation, the gripper clamp is opened by introducing a wedge-shaped or conical gripper clamp opener at an appropriate place between the arms of the gripper clamp. A weft yarn end is then introduced between the opened jaws and the clamp opener removed, whereby the jaws grip the yarn and the shuttle is passed into the shed through the teeth of the shuttle guide. The shuttle is brought to a stop in a receiving unit, and returned to the picking position by a conveyer underneath the shed. A number of shuttles are used in each machine, so that they can be returned at moderate speeds despite the rapid picking sequence. In modern weaving machines, shooting speeds of up to something like 30 meters per second and picking rates of more than 300 picks per minute are used. Known shuttles of this type generally have standard dimensions of approximately 90.times.14.times.16 millimeters and weigh about 30 to 60 grams.
U.S. Pat. No. 3,854,506 relates to a gripper shuttle wherein the shuttle housing is made of a tough impactresistant plastic while the gripper clamp and the nose at one end of the clamp are made of steel. The gripper clamp and the nose can be formed as a single unit. The shuttle housing is provided with a partition between the arms of the gripper clamp to reinforce and stiffen the housing. At least one of the clamp arms is provided with a thickened part to abut the partition when in the clamping position and thereby prevent premature wear of the arms.
U.S. Pat. No. 3,237,653 relates to a shuttle for looms comprising a housing having an open lead and then an open trailing end, a gripper spring in the housing, the gripper spring having an arcuate nose portion and a yoke portion. The arcuate nose portion is connected to the yoke portion from which spaced arms extend toward the trailing end of the housing and culminate in jaws adjacent the trailing end of the housing. Flange means connected to the housing extend over and partially close the opened trailing end to provide additional surface area to distribute the impact of the picker thereon.
U.S. Pat. No. 3,939,878 relates to a gripper shuttle for weft yarns. The shuttle is formed with a nose member which overlaps the front edges of the housing while being disposed within the projected plane of the housing. A gripper mechanism is mounted within the housing and has gripper jaws located adjacent the open end portion of the trailing end of the shuttle. The means for securing the nose member to the housing is in the form of a spigot which is received in the front end of the housing and which is integrally formed with the nose member. In addition, the securing means includes a pin which is disposed in bores of the spigot and housing to retain the spigot in the housing.
In the past, when the above-described shuttles were used in modern weaving machines at the speeds indicated, there have been times when the machines would jam or malfunction causing a shuttle to be retained in the receiving unit while another shuttle was being shot or picked through the shed. This resulted in the latter shuttle crashing into the rear of the preceding shuttle. Since the jaws of the gripper clamp in the preceding shuttle are located adjacent the open trailing end of the shuttle and since the nose portion of the shuttle crashing into it was shaped as described above, the arcuate nose portion of a second shuttle would strike the jaws of the gripper clamp of the preceding shuttle with sufficient force to cause breakage thereof. This, of course, resulted in extra expense, inconvenience, and loss of time. This is the problem overcome by the present invention.